1. Field of the Invention
The present invention relates to a printing apparatus comprising: an exposure head on which a plurality of light amount control sections are arranged in a main scanning direction, wherein a test chart can be created by the relative movement between the exposure head and a photosensitive material in a sub scanning direction that is perpendicular to the main scanning direction and by controlling the light amount control sections of the exposure head based on set exposure data during the relative movement, a scanner for acquiring scanning data by scanning the test chart, and correction data generating means by which correction data for the light amount control sections is generated based on the scanning data and stored in a correction table.
2. Description of the Related Art
As a printing apparatus configured as described above, there are printing apparatuses that create a test print sheet (a test chart of the present invention) from printing paper as a photosensitive material by performing exposure with a fluorescent print head (an exposure head of the present invention), then capture a line image of this test print sheet using a flatbed scanner, and set a correction table based on the density of exposure dot lines that have been captured. The correction table that has been obtained in this manner is used as data for correcting unevenness in the luminance of light-emitting elements arranged on the exposure head.
For example, see JP 2001-142162A (paragraph numbers [0011] to [0031], [0037], and FIGS. 1 to 15).
In this conventional technique, even numbers and odd numbers are given to fluorescent light-emitting elements corresponding to the three primary colors R (red), G (green), and B (blue) constituting the fluorescent print head, and the test print sheet is created by performing exposure on the printing paper by controlling these fluorescent light-emitting elements. On this test print sheet, the configuration is such that a plurality of test exposure dot lines corresponding to the fluorescent light-emitting elements given even numbers or odd numbers are formed, the densities of the center positions in the main scanning direction (width direction of the exposure dot lines) of the exposure dot lines that have been acquired by the flatbed scanner are acquired at a predetermined spacing in the sub scanning direction, and moreover, an average value of the density data contained in check windows is set as a representative density, and correction coefficients of the fluorescent light-emitting elements are generated from the representative density and stored in the correction table.
Describing a photo printing apparatus as an example, when photosensitive materials are manufactured by various manufacturers or when various types of paper are used, various types of sensibility (including color sensitivity) are obtained, and the color develops in various manners. For this reason, it is usual that the correction table described above is set for each of photosensitive materials. Furthermore, it is desirable that the correction table is updated as frequently as possible, and at the time of this update, the correction table is updated for the plurality of photosensitive materials.
Thus, in a conventional process, the processing procedure is such that the type of a photosensitive material is artificially set, a test chart is created using the photosensitive material, the test chart is set at a scanner, and scanning data is acquired. However, in a state where the type of a photosensitive material is set in advance, there is a case in which scanning is erroneously performed on a test chart created on a different type of a photosensitive material, and thus a proper correction table cannot be set. Furthermore, it is difficult for an operator to notice this erroneous operation, and thus an improvement has been required.